The Australian Medical Association in WA has attributed a large outbreak of mumps in the state to low vaccination rates, but the Health Department has a different view.

More than 390 cases of mumps have been reported around WA since March, compared to about 20 cases at the same time last year.

Across Australia, there have been 500 more cases of the viral infection this year compared to last, with WA accounting for almost three quarters of that spike.

The WA Health Department said the outbreak was mainly confined to remote Aboriginal communities in the north of the state, and to some people returning from overseas.

A spokeswoman said there had also been a small number of cases in Perth, but said there was no need for concern and added the department had not issued any health warnings.

"There have been a number of 'clusters' this year, mainly in the north of the state," the spokeswoman said in a statement.

"Around 15-25 cases are currently being notified each week, mostly from the Pilbara, Goldfields, Kimberley and Midwest regions.

"A few apparently sporadic locally acquired cases have been diagnosed in the Perth metropolitan area in the past fortnight.

"At present, there is no wider public health risk."

Vaccination programs lax: AMA

Australian Medical Association WA president Michael Gannon accused the Health Department of playing down the problem.

"I'm sure they would be concerned. Mumps is a very serious infection," Dr Gannon said.

We should always be concerned about outbreaks of vaccine-preventable infections.

Michael Gannon, AMA

"We have seen a significant increase this year and this is [caused] very simply by people failing to avail themselves of the MMR vaccine to prevent it.

"We are getting lax with vaccination programmes. We have consistently over the past 10 or 15 years lagged behind many other states with childhood vaccinations.

"I'm pleased to report that they are back above 90 per cent, but for many years we had vaccination rates of 85 to 90 per cent.

"The problem is when infections like mumps, highly infectious viruses, get into closed spaces like nursing homes and boarding schools, they can spread like wildfire unless people are vaccinated."

Dr Gannon urged parents to ensure their children were vaccinated against mumps and to ensure they followed up with booster shots when their children became teenagers.

"We should always be concerned about outbreaks of vaccine-preventable infections," he said.

"Mumps is one of the more benign preventable infections, but it has the ability to make people feel very sick. It has a clear association with male infertility. We shouldn't see these cases."

Vaccination rates not to blame: Health Department

The Health Department said while the reason for such outbreaks was not fully understood, it rejected the AMA's claim vaccination rates in the affected areas or WA generally were to blame.

In a statement, the department said it was more likely to be factors including a "chance introduction of mumps, probably by someone infected overseas coming into contact with a susceptible person or persons in the Kimberley".

It said while mumps vaccination would prevent most people from being infected, the reported effectiveness of one dose was in the range of 69 to 81 per cent.

The figures were higher for two doses, but the vaccine did not offer 100 per cent protection.

"Evidence from the WA outbreaks and similar outbreaks overseas also suggests that immunity from the mumps also wanes over time, particularly in those who were vaccinated more than 10 years previously," it said.

"Spread of mumps is also more likely to occur in situations where there is relatively more close social mixing, such as occurs in crowded households, which is probably relevant to the spread in Aboriginal communities and in school and in university residential settings."